Algorithm for autocomplete?

Question

I am referring to the algorithm that is used to give query suggestions when a user types a search term in Google.

I am mainly interested in: 1. Most important resul

Answer 1

Take a look at Firefox's Awesome bar algorithm

Google suggest is useful, because it take the millions of popular queries + your past related queries into account.

It doesn't have a good completion algorithm / UI though:

1. Doesn't do substrings
2. Seems like a relatively simple word-boundary prefix algorithm.
   For example: Try tomcat tut --> correctly suggest "tomcat tutorial". Now try tomcat rial --> no suggestions )-:
3. Doesn't support "did you mean?" - as in google search results.